[radvd-devel-l] [PATCH] Sending initial RAs in smaller intervals

[Pekka Savola]

Hi,

Sure -- unless I hear comments on this, I'll merge this before the 
next release.

On Tue, 7 Feb 2006, Jirka Bohac wrote:
> RFC 2461, section 6.2.4 says:
>   For the first few advertisements (up to
>   MAX_INITIAL_RTR_ADVERTISEMENTS) sent from an interface when it
>   becomes an advertising interface, if the randomly chosen
>   interval is greater than MAX_INITIAL_RTR_ADVERT_INTERVAL, the
>   timer SHOULD be set to MAX_INITIAL_RTR_ADVERT_INTERVAL
>   instead.  Using a smaller interval for the initial
>   advertisements increases the likelihood of a router being
>   discovered quickly when it first becomes available, in the
>   presence of possible packet loss.
>
> radvd does not do this, even though the constants are already
> defined in defaults.h.
>
> The following patch fixes that:
>
> diff -Naur radvd-0.9.1/radvd.c radvd-0.9.1-patched/radvd.c
> --- radvd-0.9.1/radvd.c	2005-12-30 16:13:11.000000000 +0100
> +++ radvd-0.9.1-patched/radvd.c	2006-02-07 18:44:09.000000000 +0100
> @@ -302,6 +302,12 @@
> 	send_ra(sock, iface, NULL);
>
> 	next = rand_between(iface->MinRtrAdvInterval, iface->MaxRtrAdvInterval);
> +	if (iface->InitialAdvLeft > 1) {
> +		--iface->InitialAdvLeft;
> +		if (next > MAX_INITIAL_RTR_ADVERT_INTERVAL)
> +			next = MAX_INITIAL_RTR_ADVERT_INTERVAL;
> +	}
> +
> 	set_timer(&iface->tm, next);
> }
>
> @@ -339,9 +345,11 @@
> 			if (iface->AdvSendAdvert)
> 			{
> 				/* send an initial advertisement */
> +				iface->InitialAdvLeft = MAX_INITIAL_RTR_ADVERTISEMENTS - 1;
> 				send_ra(sock, iface, NULL);
>
> -				set_timer(&iface->tm, iface->MaxRtrAdvInterval);
> +				set_timer(&iface->tm, iface->MaxRtrAdvInterval > MAX_INITIAL_RTR_ADVERT_INTERVAL ?
> +					    MAX_INITIAL_RTR_ADVERT_INTERVAL : iface->MaxRtrAdvInterval);
> 			}
> 		}
> 	}
> diff -Naur radvd-0.9.1/radvd.h radvd-0.9.1-patched/radvd.h
> --- radvd-0.9.1/radvd.h	2005-12-30 17:12:23.000000000 +0100
> +++ radvd-0.9.1-patched/radvd.h	2006-02-07 18:44:09.000000000 +0100
> @@ -70,6 +70,7 @@
> 	int			AdvDefaultPreference;
> 	int			AdvSourceLLAddress;
> 	int			UnicastOnly;
> +	int			InitialAdvLeft;
>
> 	/* Mobile IPv6 extensions */
> 	int			AdvIntervalOpt;
>
>
>
>
>
> Please, is it possible to merge this?
>
>
> Thanks,
>
>

-- 
Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings